1. Field of Invention
The present invention relates to building exteriors, and interior wall and ceiling covering using curtain wall systems; said systems having box top shaped composite panels hung on the exterior building sheathing or other framework.
2. Background of the Invention
There are two basic type of systems for the curtain wall aluminum composite material (ACM) market. They are a wet and a dry system. A wet system uses a sealant as its primary seal against moisture. A dry system uses a gasket as its primary seal against moisture.
Most patented curtain wall systems pertain to flat glass panel type curtain wall panels. A brief summary of this flat glass panel support structure art follows below.
U.S. Pat. No. 3,548,558 (1970) to Grossman discloses a mullion system (vertical members between window lights) for a curtain wall exterior. An anchor 101 supports a plate which supports a mullion column having segments 107.
U.S. Pat. No. 3,978,629 (1976) to Echols Sr. discloses a glass panel thermal barrier vertical mullion. Each mullion has an exterior member with a track for maintenance conveyances and has an interior metal member, and has a insulating foam layer therebetween.
U.S. Pat. No. 4,015,390 (1977) to Howorth discloses a glazing structure for a glass panel/curtain wall building.
U.S. Pat. No. 4,121,396 (1978) to Oogami et al. discloses a curtain wall frame structure having channel crossings with four integral legs and backup bars.
U.S. Pat. No. 4,418,506 (1983) to Weber et al. discloses a curtain wall frame structure adding a insulating separator (56) and an insulated bolt to a known frame structure for insulation.
U.S. Pat. No. 4,471,584 (1984) to Dietrich discloses a skylight system with a unique support structure to support a curtain wall flat.
U.S. Pat. No. 4,841,700 (1989) to Matthews discloses a two-piece mullion frame for reducing the face dimension of an aluminum frame.
U.S. Pat. No. 4,996,809 (1991) to Beard discloses a flat panel skylight support frame having built in condensate gutters.
U.S. Pat. No. 5,065,557 (1991) to Laplante et al. discloses a dry gasket seal frame structure for a curtain wall which uses a flat curtain wall panel having inner and outer panel faces, and a spaced apart vertical edge therebetween. A panel can be replaced without having to dismantle any portion of the curtain wall other than the damaged panel.
U.S. Pat. No. 5,199,236 (1993) to Allen discloses a flush appearance glass panel frame structure.
U.S. Pat. No. 5,493,831 (1996) to Jansson discloses a glass panel building support frame presenting a sealed glaze edge between the glass panels.
As Laplante et al. teaches it is advantageous to be able to replace a damaged curtain wall panel using a dry seal, and further advantageous to be able to leave the horizontal and vertical support channels in place for the replacement. The present invention meets these needs in a dry ACM system.
One patented ACM system is U.S. Pat. No. 4,344,267 (1982) to Sukolics which discloses a curtain wall frame structure which allows thermal expansion of the panels to be absorbed by the joints. A vertical channel has a pair of pivotable arms to receive the sides of adjoining panels. In the present invention the exact same ACM may be used. Sukolics requires that a sheathing be installed over the support studs of the building. Then Sukolics"" thin and relatively weak, non-structural mullions and horizontal supports can be mounted in a non-sequential (also called non-directional) fashion. This non-sequential erection fashion is preferred over sequential systems. Sequential systems require starting construction at the bottom of a building and progressing left to right, one row at a time, building one row on top of a lower row. Sukolics enables wall construction from the top down which is how rain hits the building during construction. Therefore, using Sukolics"" system a builder can erect the frame, complete the roof, then construct the curtain walls from the top down to minimize rain damage to the exposed sheathing of the building.
The present invention provides the same non-sequential method for construction; additionally adding structural mullions and horizontal supports thereby allowing direct fastening to the frame and eliminating the sheathing if desired.
The present invention provides for thermal expansion by means of using floating curtain wall members which expand and contract in their mounting tracks located in the vertical mullions and horizontal supports.
Another prior art reference is a patent pending curtain wall apparatus trademarked RRD200(trademark) by Elward Systems Corporation of Denver, Colo. A combination horizontal support and perimeter extrusion (corner brace) is used, made of aluminum. The top and one side of the curtain wall is firmly bolted to the building. Thus, no xe2x80x9cflotationxe2x80x9d of the curtain wall exists on an X-Y frame structure as is the case in the present invention. Flotation reduces stresses on the curtain wall panels during thermal and/or stresses on the curtain wall panels setting movement of the building.
Panel installation begins at the bottom with panels inter-leaving at the sides utilizing xe2x80x9cmale/femalexe2x80x9d joinery working left to right. Installation continues by stacking the next row on top of the first row and continuing the left to right sequence. Therefore, an individual panel cannot be removed from the center of the wall without removing adjacent panels.
While it is basically a xe2x80x9cdryxe2x80x9d system because of the use of wiper gaskets, exposed sealant is used in the 4-way intersections due to the male/female differences of the perimeter extrusions.
Rout and return and curtain face support is provided by the perimeter extrusions. The ACM panels are fabricated utilizing known rout and return methodology. The various perimeter extrusions for the curtain wall panels are four different extrusions making the panel xe2x80x9chandedxe2x80x9d. The present invention uses panels which are symmetrical, facilitating installation.
The system does include a gutter, but it is not continuous and not part of a sub-system, and the gutter only exists on the horizontal member. Weep holes in the horizontal member allow water to flow out and over the curtain wall panels. No integrated X-Y gutter system exists.
The system requires 16-guage (non-standard) studs at precise locations for vertical attachment to the structure, thereby greatly adding to the building cost compared to the present invention. The system does not allow for a xe2x80x9cjointlessxe2x80x9d appearance because it doesn""t have a face cap that can be flushed or recessed from the face of the panel. The system does not allow for multiple xe2x80x9cjointxe2x80x9d colors.
Perimeter extrusions are not the same depth, thus requiring complex shimming; sequential, non-subsystem installation does not allow for integrated three dimensional panels to be incorporated within the system (i.e. signage or column covers, or accent bands that are not flat). The system does not allow for three dimensional joints like a rounded bullnose that would protrude away from the panel.
Another prior art system, shown in FIGS. 1-3, is the Miller-Clapperton MCP System 200-D(trademark) (referred to herein as xe2x80x9cthe MCP systemxe2x80x9d). The MCP system employs panels made of aluminum composite material (ACM) 1000 as components of an exterior curtain wall or facade of a building. As shown in the vertical sectional view of FIG. 2, a horizontal attachment support 30xe2x80x2 is screwed into sheathing, such as plywood, or through non-structural sheathing, such as gypsum board, into structural building members using structural screws 70xe2x80x2. Vertical corner clips 3xe2x80x2 and 40xe2x80x2 are used to attach the panel 1000 to the horizontal attachment support 30xe2x80x2. The clips 3xe2x80x2 and 40xe2x80x2 attach only to the return leg 22 of panel (i.e., the portion of the panel that is folded 90-degrees after a rout is performed so as to be perpendicular to the face 23) and provide no support to the face 23 of the panel. Raised positive return attachment rivets 9xe2x80x2 are used to attach the clips.
A continuous inverted support channel 60xe2x80x2 is secured by a plurality of self-drilling fasteners 5xe2x80x2 that penetrate horizontal attachment support 30xe2x80x2. A continuous snap cover 80xe2x80x2 is provided over the channel 80xe2x80x2. Caulking C is used as the primary seal to keep air and water from the inverted support channel 60xe2x80x2. Systems that use caulking as a primary seal are referred to in the industry as a xe2x80x9cwetxe2x80x9d system. Among the disadvantages of this design, is that failure of the caulking may result in uncontrolled water entering the building. For example, water may enter through the points at which the fasteners 5xe2x80x2 and 70xe2x80x2 penetrate the horizontal attachment support 30xe2x80x2.
As shown in the horizontal sectional view of FIG. 1, vertical attachment support 2xe2x80x2 is screwed into sheathing, such as plywood, or through non-structural sheathing, such as gypsum board, into structural building members using structural screws 6xe2x80x2. Vertical corner clips 3xe2x80x2 and 40xe2x80x2 are used to attach the panel 1000 to the horizontal attachment support 30xe2x80x2. The clips 3xe2x80x2 and 40xe2x80x2 attach only to the return leg 22 of panel and provide no support to the face 23 of the panel. Raised positive return attachment rivets 8xe2x80x2 are used to attach the clips. A continuous inverted support channel 4xe2x80x2 is secured by a plurality of self-drilling fasteners 5xe2x80x2 that penetrate vertical attachment support 2xe2x80x2. A continuous snap cover 7xe2x80x2 is provided over the channel 4xe2x80x2. Caulking C is used as the primary seal to keep air and water from the inverted support channel 4xe2x80x2. As above, failure of the caulking may result in uncontrolled water entering the building. For example, water may enter through the points at which the fasteners 5xe2x80x2 and 6xe2x80x2 penetrate the vertical attachment support 2xe2x80x2.
In the MCP system, the horizontal attachment supports 30xe2x80x2 and vertical attachment supports 2xe2x80x2 used to support the panels 1000 do not have gutters or channels for directing moisture away from the building and do not offer a secondary or failsafe water seal. As discussed above, a disadvantage of this design is that failure of the caulking may result in uncontrolled water entering the building, such as for example through the points at which the fasteners penetrate the horizontal and vertical attachment supports.
Another disadvantage of the MCP system is that, as shown in FIG. 3, the horizontal and vertical attachment supports are not mechanically attached. To the contrary, these members merely abut one another, rather than being mechanically attached as a continuous, integrated structure. Another disadvantage of the MCP system is that each of the vertical attachment supports requires two 18 gauge metal studs for attachment, because these members do not interface mechanically. More generally, because neither the horizontal nor the vertical supports act as structural elements, these members require support from the building structure.
The MCP system uses three different extrusions (i.e., corner clips 3xe2x80x2 and 40xe2x80x2) to attach the panels 1000 to the horizontal and vertical supports. As shown in FIG. 1, the extrusions on the sides of the panels (3xe2x80x2) are similar and are continuous along those edges. However, as shown in FIG. 2, the extrusion on the top of the panel (40xe2x80x2 on the lower panel) is a clip that inserts into a channel in the horizontal attachment support 30xe2x80x2, rather than being secured using a fastener 5xe2x80x2, as is the extrusion on the bottom of the panel (40xe2x80x2 on the upper panel). Accordingly, the panel has a defined top and a bottom because of these different extrusions, i.e., the orientation of the panel cannot be changed after the extrusions have been attached to the panel. Each of these three types of extrusions attach to the return leg 22 of the panel through the use of a pop rivet 8xe2x80x2 and 9xe2x80x2.
One disadvantage of this configuration is that the extrusions do not provide corner support to the face 23 of the panel. This allows the return leg 22 to flex, which applies stress to the 0.020xe2x80x3 aluminum corner (the panel 1000 is typically 3 mm, 4 mm, or 6 mm thick, but when the inside face and the polyethylene core are routed out from the back to form the return leg 22, all that remains to hold the return leg 22 to the front of the panel 23 is the 0.020xe2x80x3 aluminum face). In addition, because the extrusions are not continuous around the panel (i.e., do not form a continuous frame around the panel), the panel receives no diaphragm support and the face of the panel can distort under stress. Moreover, the three extrusions attach directly to the aluminum sub-system without a thermal break, which allows the transfer of heat and cold through the curtain wall.
In view of the deficiencies of the prior art discussed above, the new and non-obvious enhancements to curtain wall methods and apparatus provided by the present invention include: a dry system having a built in gutter system for rain and condensate, a failsafe moisture proof system, a flexible framework enabling vertical and horizontal support structures to be interchanged (providing flexibility during construction), support braces for the face of the curtain wall, and an alignment process for curtain wall panel alignment during construction.
The main aspect of the present invention is to provide a non-sequential, dry ACM system having structural mullions which can be mounted to the raw studs of a building.
Another aspect of the present invention is to provide a built in gutter system for the vertical mullions and the horizontal supports, thereby providing a failsafe moisture prevention system.
Another aspect of the present invention is to provide a support for the face of the curtain wall panel.
Another aspect of the present invention is to provide a framework having interchangeable vertical and horizontal mounting options.
Another aspect of the present invention is to provide for symmetrical (versus xe2x80x9chandedxe2x80x9d) panels to facilitate installation.
Another aspect of the present invention is to provide a method to align curtain wall panels during construction.
Another aspect of the present invention is to provide three curtain wall systems, wherein there exists interchangeable parts for all three systems from the curtain wall face to the bottom of the primary seal.
Other aspects of this invention will appear from the following description and appended claims, reference being made to the accompanying drawings forming a part of this specification wherein like reference characters designate corresponding parts in the several views.